/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.mycompany.calculator1;

/**
 *
 * @author hedingwei
 */
public class Calculator {   
    private double value;   
    
    public void ac(){
        value = 0;
    }   
    public void add(double number){
        value += number;
    }  
    public void substract(double number){
       if(value==0){
             value=number;
         }
         else{
             value -= number;
         }
    }
     public void divide(double number){ 
        try{
            if(value==0){
                value=number;
            }else{
            value = value/number;
            }
        }catch(Exception e){
            // TODO
        }    
    }
    public void multiply(double number){
        if(value==0){
            value=number;
        }
        else{
        value *= number;
        }

    }
    public double getValue() {
        return value;
    }
    public static void main(String[] args){
        Calculator calculator = new Calculator();
        calculator.add(10);
        calculator.substract(1);
        calculator.multiply(2);
        calculator.divide(2);
        System.out.println(calculator.getValue());
        calculator.ac();
        System.out.println(calculator.getValue());
    }
    
}
